Blind rivet stem trimmer



July 18, 1961 SMITH 2,992,482

BLIND RIVET STEM TRIMMER Filed March 3, 1959 2,992,482 Patented July 18,1961 2,992,482 BLIND RIVET STEM TRIMMER Everett 1). Smith, Lynwood,Calif, assignor to Northrop Corporation, Beverly Hills, Calif., acorporation of California Filed Mar. 3, 1959, Ser. No. 796,878 1 Claim.(Cl. 30-467) This invention relates to cutting tools and moreparticularly to a tool for removing the extending shank portion of ablind rivet or like fastener.

The performance of tools, for example conventional metal saws, diagonalcutters and the like utilized in the removal of the extending orprojecting shank portion of blind rivets and like fasteners, also theresults forthcoming from an operation of this type, are generallyunsatisfactory. An operation, performed with currently available toolsof the above type, may result in the loosening of rivets relative to themembers which they secure; the rivets themselves may be damaged or thesurface surrounding the rivets may be marred.

The cutting or trimming tool as disclosed herein includes an adaptermounted on a fluid type rotary motor; the adapter, however, may be usedwith any type rotary motor. Specifically the instant tool is utilized toremove the projecting shank portions of blind rivets whereby asubstantially flush relationship is provided between a rivet and a planesurface of structure surrounding the rivet.

An objectof the present invention is to: provide a cutting tool forremoving the projecting shank portions of blind rivetsor like fastenersin substantially flush relation with respect to an outer plane surfaceof structure secured by the rivets.

Another object is to provide a cutting tool for removing the shankportions of blind rivets and like fasteners which does not damage therivets or mar a surrounding surface during the operation.

Another object is to provide a cutting tool for removing the projectingshank portions of blind rivets which is of a compact light weightconstruction rendering the tool extremely mobile.

Although the characteristic features of the present invention areparticularly pointed out in the appended claim, the invention itself,also the manner in which it may be carried out, will be betterunderstood by referring to the following description taken in connectionwith the accompanying drawings forming a part of this application and inwhich:

FIGURE 1 is a perspective view of one embodiment of a cutting tool asdisclosed herein.

FIGURES 2 and 3 are side and plan views, respectively, of an adapterusable with the motor shown in FIG- URE 1.

Referring to the drawings in FIGURE 1 the numeral 11 identifies apreferred embodiment of the cutting tool as disclosed herein. The tool11 includes a fluid type rotary motor 12 and a fitting or adapter 14.

The motor 12 may be of any type capable of imparting high speed rotarymotion to its output member. The fluid type rotary motor shown in FIGURE1 includes a body portion 16, an output member 17, trigger means 18 andmeans 19 located at the aft end of the body portion adapted to receive ahose (not shown) through which pressurized air is supplied to the motor12.

Mounted on the outer end of the output member 17 is a circular disk-likemember 21 having teeth formed in and defining the periphery of the disk.As mounted on the member 17 the outer face of the disk 21 extends beyondor at least has a flush relation with the outer end of the member 17.The member 17 has a right angle relation with respect to the axis of thebody portion 12; this relation provides an advantage which will becomeapparent as the disclosure progresses.

In the embodiment shown in FIGURE 1 the adapter 14 includes a baseportion 22 of strap-like configuration and an upstanding portion 23 ofcylindrical configuration. The forward end of the base portion isenlarged as indicated by the numeral 24 and has a circular aperture 26formed therein. The aft end portion 27 of the base por-. tion has aright angle relation with respect to the portion 24. Provided at theextreme end of the portion 27 is an aperture (not shown) which, togetherwith portion 23, provides means for securing the adapter 14 to the motor12.

The upstanding portion 23 is secured to the portion 24 in concentricrelation with respect to the aperture 26. The portion 23 is cutaway toprovide an observation port 28 through which a rivet cutting operationmay be observed. The solid part of the portion 23, that is the portionabove the port 28, is longitudinally slit as indicated at 29 to allowexpansion and contraction of the portion 23. Ears 31 are providedadjacent each side of the slit 29 which together with a screw memberprovide means for closing the upper portion of the portion 23.

The adapter 14 is rigidly secured to the motor 12 by means of thecontracting feature of the portion 23 and the aperture provided in theportion 27 substantially as shown in FIGURE 1. The aft end of the bodyportion 16 passes through the aperture in the portion 27 and ismaintained in this position by a nut 32; the upstanding portion 23 isattached to the motor 12 by means of the ears 31 and associated screwmember.

With the adapter 14 assembled on the motor 12 in the above manner itwill be seen that the cutter 21 is located in the aperture 26 so that asubstantially coplanar rela tion is present respectively between theupper and lower faces of the portion 24 and cutter 21. In this respectthe lower surfaces of the cutter and portion 24 are located in a commonplane regardless of the exact relationship of corresponding uppersurfaces. Further, it will be seen that the axis of the output member 17has a normal relation with respect to the lower surface of the portion24. The diameter of the aperture 26 is such as to provide predeterminedclearance therebetween and the cutter 21.

Formed in the portion 24 is a radial slot 33 extending between theaperture 26 and the edge of the portion 24. The slot 33 is of sufiicientwidth to receive the shank portion of a blind rivet to be cut and islocated so that the center line thereof substantially coincides with thelongitudinal center line of the adapter 14. The slot 33 may be locatedelsewhere in the portion 24, however, experience has shown that theabove location is the most satisfactory.

Mounted on one side of the slot 33 by means of a screw or the like is anL-shaped block 34. The purpose of this block is to support the shank ofa rivet until the latter is completely cut or parted from the remainderof the rivet. The upright portion of the block 34 extends apredetermined distance beyond the perimeter of the aperture 26 and in sodoing provides better support of a rivet shank being cut and alsominimizes the possibility of a rivet shank from being drawn into theclearance space provided between the cutter and portion 24. The Workingface of the block 34- has a flush relationship with one side of the slot33, in this instance the near side of the slot 33 assuming that thecutter rotates in a clockwise direction as viewed from above as shown inFIGURE 1.

The embodiment of the adapter 36 as shown in FIG- URES 2 and 3 is quitesimilar to the adapter of FIGURE 1- The strap-like base portion 22 ofFIGURE 1 is replaced by a plate-like base portion 37 in FIGURES 2 and 3.The upstanding portion 38 is similarto the portion 23 of FIGURE 1,however, a pair of diametrically opposed observation ports are providedin the portion 38. Otherwise the adapter 36 is similar in constructionto the adapter 14 of FIGURE 1. However, the adapter 36 is secured inposition on the motor 12 by the upstanding portion 38 only. Whenassembled on the motor 12 the side surfaces of the plate 37,particularly the lower surface of the plate 37, are normal to the axisof the output member 17 and the lower surfaces of the cutter and theplate porion 37 lie in a common plane.

In operation the lower surface of the portion 24 (FIG- URE 1) or thelower surface of the portion 37 (FI URE 2 and 3) rests on a planesurface of structure through which the shank portion of a blind rivetextends. With the lower surface of the portion 24 or of the portion 37in firm contact with the surface of the structure through which a blindrivet extends, the extending portion of the rivet is fed into the slot33 and urged into contact with the cutter 21. The cutter 21, having aparallel relation with respect to the aforementioned plane surface ofthe structure and rotating at a high rate of speed, quickly andefficiently parts the extending shank portion of the rivet substantiallyflush with plane surface of the structure without marring or defacingthe latter in any respect. 7

In view of the above description it will be seen that a cutting toolcapable of carrying out the various objects of the invention isdisclosed. By using a motor of the type shown in FIGURE 1, that is amotor in which the output member thereof has a right angle relation withrespect to the body portion of the motor, a well balanced tool which iseasy to handle and manipulate is provided.

While in order to comply with the statute, the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown,

but that the means and construction herein disclosed comprise apreferred form of putting the invention into effect, and the inventionis therefore claimed in any of its forms or modifications within thelegitimate and valid scope of the appended claim.

What is claimed is:

A cutting tool including a rotary motor having an output member and anadapter; the relation of said motor and output member being furthercharacterized in that the axes of said output member has a normalrelation with respect to the axis of rotation of said motor; a disk-likecutting element mounted 011 the outer end and rotating with said outputmember; said adapter being constructed of strap-like material includingbase and securing portions; said base portion having outer edges and acircular aperture formed therein; an upstanding attaching member securedto said base portion; said adapter being mounted on said motor and beingfurther characterized in that said securing portion and upstandingmember are respectively attached to the opposite ends of said motor sothat said base portion has a parallel relation with respect to the axesof rotation of said motor and the side surfaces of said cutting elementhave a coplanar relation with respect to the side surfaces of said baseportion; said base portion having a radial slot formed therein extendingbetween said aperture and an outer edge thereof; and a plate-like stopmember secured to said base portion with one side thereof aligned withan edge of said slot and an end portion of said stop member extending apredetermined distance inboard of the perimeter of said aperture.

References Cited in the file of this patent UNITED STATES PATENTS2,248,694 Boyette July 8, 1941 2,562,143 Godfrey et a1. July 24, 1951FOREIGN PATENTS 1,002,118 Germany Feb. 7,

